The invention relates to a tape cassette for use with a cassette tape recorder.
A tape cassette for use with a cassette tape recorder is in widespread use today, but involves a number of drawbacks which must be overcome to provide a satisfactory recorder operation. A tape cassette as used with a cassette tape recorder is formed with a plurality of tape exposure ports along its one lateral edge, including a first port for engaging the tape between a capstan and a pinch roller, a second port for permitting abutment of the tape against an erase magnetic head, and a third and/or a fourth port for permitting an abutment of the tape against a record and/or playback magnetic head. Usually the tape cassette is molded into a pair of casing halves which are fitted together to form a cassette casing. The tape exposure ports mentioned above are defined by a plurality of pairs of frame portions which extend from the respective casing halves. In the conventional construction, the oppositely located frame portions extend an equal length from the respective casing halves so that they abut each other along the centerline of a tape passageway. This results in disadvantages that during a tape cassette assembling operation, the tape which is passed along the exposure ports may be misled into and held between the abutting frame portions to cause a damage to the tape or to cause a waste in the assembling time. To overcome these difficulties, there has been a proposal to configure the abutting frame portions such that they abut on one side of the centerline of the tape passageway. However, when the resulting tape cassette is loaded on a tape recorder, the tape may be jutted out through the gap between the frame portions during its running, thereby causing a damage or breakage in the tape or presenting difficulties in restoring the tape to the normal position if it is not damaged or broken. The presence of the gap cannot be avoided when the tape cassette comprises a pair of casing halves. The above problem is compounded when the fact is considered that the gap must have a substantial length in order to assemble the both casing halves with a high accuracy.